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<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        // 简单数据类型 BigInt（）
        // 构造函数，代码可读性
        const wes =  Symbol('Wes');
        const person = Symbol('Wes');
        // console.log(wes == person);
        const classRoom = {
            [Symbol('Mark')]:{grade:50,gender:'male'},
            [Symbol('oliva')]:{grade: 80,gender:'female'},
            [Symbol('oliva')]:{grade: 85,gender:'female'},
            "dl":["国文","陈倩文"]
        }
        //console.log(classRoom);
        // for key in 
        // symbol key 不可以被枚举
        for (const person in classRoom) {
            console.log(person,'////');
        }

        const syms = Object.getOwnPropertySymbols(classRoom);
        // console.log(syms);
        const data = syms.map(sym => classRoom[sym]);
        console.log(data);
    </script>
</body>
</html>